Defective Seat-Belt Buckles - Geordie1
A feature in 'Which' magazine News:Cars article dated 4th January 2007 indicates that latest safety tests have revealed that poor seat-belt buckle design in several cars could cause them to be accidentally released by flailing arms etc in an accident situation whereby occupants are vulnerable to injury or even risk being thrown from the car in a crash.

It further states that cars made by Chrysler, Honda, Mitsubishi, Subaru and Volvo all had models affected by this type of buckle design.

The worrying factor is that when 'Which' called upon these manufacturers to change the buckle desgn on affected models, only Volvo agreed to look into the problem.
Defective Seat-Belt Buckles - Geordie1
For info the following is the full list of all vehicle relevant to alleged defective seat-belt buckles:-

Honda Civic 1.8; Misubishi Grandis 2.4; Nissan X-Trail 2.2; Nissan Note 1.4; Seat Leon 1.6; Subaru Legacy Tourer 2.0; Volvo S80; Chrysler 300C CRD.

In addition the following cars were deemed to have insufficient protection against upper leg damage in the event of a crash:-

Fiat Sedici 1.6; Hyundai Santa Fe 2.2 Diesel; Mitsubishi Grandis 2.4; Peugeot 207 1.4; Seat Leon 1.6; Skoda Roomster 1.4; Suzuki SX4 1.6; Vauxhall Corsa 1.2; VW Eos 2.0; Chrysler 300C CRD
Defective Seat-Belt Buckles - LeePower
Skoda Roomster also has a know issue where the battery cables can be damaged in a front on accident, In the first crash tests the cables where severed & this caused the seatbelt pretensioners to fail & not fire.

Skoda did try to fix it when they where told about this by Euro Ncap but it wasn't a 100% success & more importantly Skoda refuse to recall earlier Roomsters & fix them.
Defective Seat-Belt Buckles - Murphy The Cat
Does anyone in the backroom who subscribes to Which add a few more details to what Geordie is talking about, as Which online is very limited.
MTC
Defective Seat-Belt Buckles - IanJohnson
Who were the experts employed by which to produce this report and where did the data come from.

I would prefer to trust EURONCAP who actaully test cars rather than Which!
Defective Seat-Belt Buckles - LeePower
Also all the EuroNcap tests are free to view to anybody online unlike the Which tests.